Sharks don't have bones. They are a special type of fish known as "elasmobranchs", which translates into fish made of cartilaginous tissues. Even though sharks don't have bones, they still can fossilize. As most sharks age, they deposit calcium salts
The Dancing Plague of 1518: In 1518, people in Strasbourg, France, started dancing uncontrollably. One woman began, and soon many others joined, dancing for days. Some historians think they had mass hysteria or food poisoning from moldy rye.
Benjamin Franklin is credited with the actual invention of the rocking chair in 1710, although other sources claim it was invented by farmers or by early cabinetmakers.
